Through the first four months of 2016, Vietnamese health officials have reported 25,441 cases of dengue including 10 deaths in approximately two-thirds of the provinces. This is an increase of 179 percent compared to the same period in 2015 (through May 10 last year, Vietnam saw 10,892 cases of dengue).
Health officials also note that compared to the median in 2010-2014 period, the cumulative number of cases increased by 124%.
In all of 2015, Vietnam reported 97,476 cases of dengue, including 61 deaths, reported in 54 out of 63 provinces in the country.
Dengue is a viral infection transmitted by the bite of an infected mosquito. There are four closely related but antigenically different serotypes of the virus that can cause dengue (DEN1, DEN 2, DEN 3, DEN 4).
Dengue has a wide spectrum of infection outcome (asymptomatic to symptomatic). Symptomatic illness can vary from dengue fever (DF) to the more serious dengue hemorrhagic fever (DHF).
- Dengue Fever (DF) – marked by an onset of sudden high fever, severe headache, pain behind the eyes, and pain in muscles and joints. Some may also have a rash and varying degree of bleeding from various parts of the body (including nose, mouth and gums or skin bruising).
- Dengue Hemorrhagic Fever (DHF) – is a more severe form, seen only in a small proportion of those infected. DHF is a stereotypic illness characterized by 3 phases; febrile phase with high continuous fever usually lasting for less than 7 days; critical phase (plasma leaking) lasting 1-2 days usually apparent when fever comes down, leading to shock if not detected and treated early; convalescence phase lasting 2-5 days with improvement of appetite, bradycardia (slow heart rate), convalescent rash (white patches in red background), often accompanied by generalized itching (more intense in palms and soles), and diuresis (increase urine output).
In the past 50 years, the incidence of dengue worldwide has increased 30-fold, largely as a consequence of the growth of cities and increased travel.
According to a 2013 WHO report between 1955 and 1959, the number of countries reporting cases of dengue increased from three to eight; in 2012, the geographical distribution of dengue included more than 125 countries.
The World Health Organization (WHO) estimates there may be 50–100 million dengue infections worldwide every year. However,there was 2013 research from the University of Oxford and the Wellcome Trust, using cartographic approaches, estimate there to be 390 million dengue infections per year worldwide.